Post on 15-Jul-2020
Coastal Resilience Project Updates
Shoreline Management Model v. 5
Christine TomblesonCCRM Tidal Wetlands Workshop
May 2, 2019
Comprehensive Coastal ShorelineManagement Portals (CCRMPs)
• A Portal is a specially designed website that serves as the single point of access for a variety of information
Comprehensive Coastal ShorelineManagement Portals (CCRMPs)
• Provide Information, data, and tools to assist localities
• Implementation of tidal shoreline laws and policy established by the Virginia General Assembly
www.vims.edu/ccrm/ccrmp
• Every Tidewater locality has their own specific portal
Comprehensive Coastal ShorelineManagement Portals (CCRMPs)
Comprehensive Coastal ShorelineManagement Portals (CCRMPs)
Comprehensive Coastal ShorelineManagement Portals (CCRMPs)
Comprehensive Map Viewer
BMP = Best Management Practice
Comprehensive Map Viewer• Preferred Shoreline BMPs
Recommendations reflect Commonwealth’s policy: Living shoreline practices are the preferred
alternatives where possible.
• Recommendations intended to address eroding/failing shorelines
• Control erosion• Have ecological benefits• Contribute to coastal resiliency
• Based on available shoreline conditions
• Preferred shoreline erosion control practices/approaches
Shoreline Management Model
• Spatial, GIS based model (Data is mapped)• Static model (Snap-shot in time)
• Determines the appropriate BMP for an eroding/failing shoreline
• Based on the available shoreline condition data at the time of inventory
• Uses decision tree logic
Shoreline Management Model – Decision Tree Logic
Shoreline Management Model – Decision Tree LogicStart
Shoreline Management Model – Decision Tree Logic
Preferred BMP
Start
Shoreline Management Model (v.5)Shoreline conditions factored into the model include:
• Bank height
• Nearshore bathymetry – Water depth
• Proximity of upland development
• Presence or absence of natural buffers (tidal marshes, beaches, riparian forests)
• Wave exposure (fetch) - Energy
Shoreline Management Model (v.5 )
What’s New?
Shoreline Management Model (v.5)1) Model now factors in existing shoreline defense structures
Shoreline Management Model (v.5)2) Preferred BMP Recommendation (slight) Changes
Previous Recommendations• Maintain/Enhance/Create Marsh
and/or Riparian Buffer• Plant Marsh with Sill• Groin Field with Beach Nourishment• Maintain Beach or Offshore
Breakwater with Beach Nourishment• Revetment
New Recommendations• Non-Structural Living Shoreline• Plant Marsh with Sill• Groin Field with Beach Nourishment• Maintain Beach or Offshore
Breakwater with Beach Nourishment• Revetment• Bulkhead Toe Revetment
Shoreline Management Model (v.5)2) Preferred BMP Recommendation (slight) Changes
Previous Recommendations• Maintain/Enhance/Create Marsh
and/or Riparian Buffer• Plant Marsh with Sill• Groin Field with Beach Nourishment• Maintain Beach or Offshore
Breakwater with Beach Nourishment• Revetment
New Recommendations• Non-Structural Living Shoreline• Plant Marsh with Sill• Groin Field with Beach Nourishment• Maintain Beach or Offshore
Breakwater with Beach Nourishment• Revetment• Bulkhead Toe Revetment
Note: Shoreline BMP Definition• It is important to read the definition
of the BMP for more details
• Definition provides potential alternative approaches and placement of BMP and other details:
• Based on:• Ability to grade bank• Navigation needs/limitations• Length of shoreline being
treated
• Helps determine the best BMP approach for the shoreline
Note: Shoreline BMP Definition
Shoreline BMP Glossary
Shoreline BMP Glossary
Shoreline Management Model (v.5)2) Preferred BMP Recommendation (slight) Changes
Previous Recommendations• Maintain/Enhance/Create Marsh• Plant Marsh with Sill• Groin Field with Beach Nourishment• Maintain Beach or Offshore Breakwater
with Beach Nourishment• Revetment• Area of Special Concern
• Residential canals• Industrial and commercial hardened
shoreline • Sand spits
Shoreline Management Model (v.5)2) Preferred BMP Recommendation (slight) Changes
Previous Recommendations• Maintain/Enhance/Create Marsh• Plant Marsh with Sill• Groin Field with Beach Nourishment• Maintain Beach or Offshore Breakwater
with Beach Nourishment• Revetment• Area of Special Concern
• Residential canals• Industrial and commercial hardened
shoreline • Sand spits
New Recommendations• Non-Structural Living Shoreline• Plant Marsh with Sill• Groin Field with Beach Nourishment• Maintain Beach or Offshore
Breakwater with Beach Nourishment• Revetment• Bulkhead Toe Revetment• Special Consideration Areas
Shoreline Management Model (v.5)• Residential Canals
Now get a specific BMP recommendation
Shoreline Management Model (v.5)Special Consideration Areas• Highly Modified Areas
Industrial and Commercial hardened shoreline areas
Shoreline management options may be limited by:
• Highly developed upland • Adjacent infrastructure (e.g. road) • Navigation needs/limitations
Recommendation:• Seek expert advice on the design of
your project.
Shoreline Management Model (v.5)Special Consideration Areas• Special Geomorphic Area
Sand Spits
Recommendation:
• Maintain the natural condition of this shoreline to allow for unimpeded sediment movement and the corresponding response of wetlands, beach and/or dune.
These features are dynamic.
• If primary structures are present and threatened, seek expert advice on the design of your project.
Shoreline Management Model (v.5)Special Consideration Areas• Ecological Conflict
Management options for shorelines may be limited by the presence of Submerged Aquatic Vegetation (SAV).
Recommendation:
• Seek advice from the Virginia Marine Resources Commission Habitat Management Division http://www.mrc.virginia.gov/.
Model now factors in presence of Submerged Aquatic Vegetation (SAV)
Shoreline Management Model Updates (v.5) SUMMARY
• The model now factors in:• Existing defense structures and SAV along a shoreline
• Bulkhead Toe Revetment is now a recommendation
• Maintain/Enhance/Create Marsh and/or Riparian Buffer is now called Non-Structural Living Shoreline
• Areas of Special Concern are no longer in model• Residential Canals now get a specific BMP
• Special Consideration Areas (new) – Areas where preferred management options may be limited• Highly Modified Area• Special Geomorphic Area• Ecological Conflict
Questions?
Christine TomblesonCenter for Coastal Resources Management
804-684-7912 Christine@vims.edu